Life Sciences Commons^™

Habitat Use And Movement Patterns Of Two Redwood Forest Salamanders, Aneides Vagrans And Ensatina Eschscholtzii, With An Examination Of The Efficacy Of Pit Tags For Marking Small Plethodontids, Christian Brown

Cal Poly Humboldt theses and projects

The habitat use and movements of small, secretive salamanders are generally poorly understood, in part due to the difficulty associated with marking and recapturing such animals. This study was designed to test the efficacy, both in the laboratory and in the field, of using passive integrated transponder (PIT) tags to mark and track two small-bodied plethodontid salamander species native to coastal northwestern California, Aneides vagrans, the Wandering Salamander, and Ensatina eschscholtzii, the Ensatina Salamander.

Aneides vagrans inhabits tree crowns. Using cover objects and visual encounter surveys, I searched for A. vagrans in the angiosperm understory canopy at least twice …

Movement, Habitat, And Home Range Of Introduced Bullfrogs (Lithobates Catesbeianus) On Mad River Gravel Ponds (Humboldt Co., Ca, Usa), With Implications For Hydro-Modification As A Method Of Management, Madeline C. Cooper

Cal Poly Humboldt theses and projects

American Bullfrogs are a non-native, invasive species in California (USA), where they are known to have deleterious effects on many native species. Carnivorous adults prey on native amphibians and fish, while herbivorous tadpoles outcompete native tadpoles for algal food resources. Bullfrogs have been successful at colonizing old tailing ponds and other pools left over from mining activities, and these relict pools are common on many rivers in California. Information on the dispersal capabilities of Bullfrogs could help predict range expansions and inform management decisions. Unfortunately, this information is lacking from both their native and invaded range. From May to August …

Modeling The Spread Of Sudden Oak Death Across A Heterogeneous Landscape In Redwood National Park Using A Spatially-Explicit Epidemiological Model, Laura A. Morgan

Cal Poly Humboldt theses and projects

The pathogen Phytophthora ramorum, the causal agent of Sudden Oak Death (SOD), is responsible for the deaths of millions of oak (Quercus spp.) and tanoak (Notholithocarpus densiflorus) trees in California and Oregon (USA). A recent infection in Redwood National Park (RNP) in California (USA) provided an opportunity to adapt an existing SOD model to assess the efficacy of current and proposed management strategies. A common method of SOD treatment includes killing both infected and uninfected hosts in the area of infection, as well as the area surrounding the infection to create buffers to account for undetected …

In The Face Of Drought: Do Fuel Treatments Promote Resistance To Multi-Year Drought In A Mixed-Conifer Forest Of Northern California?, Michael Vernon

Cal Poly Humboldt theses and projects

Climate change is predicted to increase the frequency, duration, and severity of drought events across many bioregions. Forest managers have two active management techniques to promote resistance and resilience to drought: prescribed fire and mechanical thinning. Generally applied to reduce fuels and fire hazard, treated areas may also reduce competition for resources that may improve tree-growth during drought and reduce mortality. The recent severe and prolonged drought in California allowed me to investigate the effects of climate stress and fuel treatments on tree growth responses in a dry mixed-conifer forest ecosystem.

To assess tree-growth responses to fuel treatments during severe …

A Comparison Of Benthic Macroinvertebrate Assemblages Between Perennial And Intermittent Headwater Streams Of The Mattole River In Northern California, Usa, Mason S. London

Cal Poly Humboldt theses and projects

Intermittent streams are common throughout the world and comprise 60% or more of total river lengths in the conterminous United States. Despite their prevalence, intermittent streams are understudied, particularly first-order headwater streams, which are vital for maintaining the function, health and biotic diversity of river networks. In June 2016, I sampled five intermittent and five perennial headwater streams in the Mattole River watershed in northwestern coastal California, USA, to compare benthic macroinvertebrate (BMI) assemblages between intermittent and perennial streams. BMI samples were collected using a 500µm mesh D-net at eight randomly located riffles along a 150-m reach, and then composited, …

The Influence Of Canopy Cover And Climate On Early Life-Stage Vital Rates For Northern Red-Legged Frogs (Rana Aurora), And The Implications For Population Growth Rates, Kecly Mcharry

Cal Poly Humboldt theses and projects

Many amphibian species are in decline due to habitat loss and changing climates. Understanding how habitat characteristics and climate influence vital rates, and if they act in concert or in opposition can inform management decisions. This study investigated the potential interaction of canopy cover and climate on early stage vital rates of northern red-legged frogs. Demographic data were collected from sample populations in experimental canopy cover treatments across a latitudinal distribution. Rearing cages were used to estimate hatch success, and mark-recapture surveys to estimate tadpole survival. Ambient air temperature was used as an index of climate because it is easily …

An Estimation Of Potential Salmonid Habitat Capacity In The Upper Mainstem Eel River, California, Emily J. Cooper

Cal Poly Humboldt theses and projects

In Northern California’s Eel River watershed, the two dams that make up the Potter Valley Project (PVP) restrict the distribution and production of anadromous salmonids, and current populations of Chinook Salmon (Oncorhynchus tshawytscha) and steelhead trout (O. mykiss) in the upper mainstem Eel River are in need of recovery. In anticipation of the upcoming FERC relicensing of the PVP, this project provides an estimation of the extent of potential salmonid habitat and its capacity for steelhead trout and Chinook Salmon in the upper mainstem Eel River watershed above the impassable Scott Dam. Using three fish passage …

Darlingtonia Californica Phytotelma Organisms: Spatial Relations Within The Metacommunity, Stefani Marie Brandt

Cal Poly Humboldt theses and projects

The California pitcher plant, Darlingtonia californica, provides a unique setting to research community ecology because it harbors small ponds of water, or phytotelmata, in its modified leaves. Each phytotelma hosts a unique community of various invertebrates who live among carcasses of drowned plant prey. These pitchers and their inquiline communities are relatively small yet abundant in the wild, resulting in an ideal natural setup for community composition comparisons. There have been no previous studies that research D. californica inquiline communities across multiple geographic regions concurrently. This study sought to survey phytotelma communities throughout the range of D. californica at …